add para about example namespaces that already exist

diff --git a/isa_conflict_resolution/isamux_isans.mdwn b/isa_conflict_resolution/isamux_isans.mdwn
index 5bd4a122a6afa02c8ce6231ae2c6167461f669ce..d0f85e50944fcb4d4c6b6a19f9bf9afa5ae218f0 100644 (file)
--- a/isa_conflict_resolution/isamux_isans.mdwn
+++ b/isa_conflict_resolution/isamux_isans.mdwn
@@ -17,6 +17,16 @@ be relevant for a fixed number of instructions at a time.  Caveat:
 allowing such a countdown to cross branch-points is unwise (illegal
 instruction?)
 
+An example of a pre-existing "namespace" switch that has been in
+prevalent use for several decades (SPARC and other architectures):
+dynamic runtime selectability of littel-endian / big-endian "meaning"
+of instructions by way of a "mode switch" instruction (of some kind).
+
+That "switch" is in effect a 33rd (hidden) bit that is part of the opcode,
+going directly into the mux / decode phase of instruction decode, and
+thus qualifies categorically as a "namespace".  This proposal both formalises
+and generalises that concept.
+
 # Hypothetical Format
 
 Note that this is a hypothetical format, yet TBD, where particular attention